body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
}

header {
    background-color: #4CAF50;
    color: white;
    padding: 1em;
    text-align: center;
}

nav a {
    color: white;
    text-decoration: none;
    margin-left: 1em;
}

main {
    padding: 1em;
}

.hidden {
    display: none;
}

#login-section {
    margin-bottom: 1em;
}

#login-form {
    display: flex;
    flex-direction: column;
}

#login-form label {
    margin-top: 0.5em;
}

#login-form input {
    margin-top: 0.2em;
    padding: 0.5em;
}

#login-form button {
    margin-top: 1em;
    padding: 0.5em;
    background-color: #4CAF50;
    color: white;
    border: none;
    cursor: pointer;
}

#blog-posts article {
    margin-bottom: 1em;
}

footer {
    background-color: #333;
    color: white;
    text-align: center;
    padding: 1em;
    position: fixed;
    width: 100%;
    bottom: 0;
}

.popup {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background-color: rgba(0, 0, 0, 0.5);
    border: 1px solid #ccc;
    padding: 1px;

}
 
.popup-content {
    background-color: white;
    padding: 20px;
    border-radius: 5px;
    width: 300px;
    text-align: center;
    position: relative;
}
 
.close-button {
    position: absolute;
    top: 10px;
    right: 10px;
    font-size: 20px;
    cursor: pointer;
}
 
/* 欢迎信息样式 */
.welcome-message {
    position: fixed;
    top: 10px;
    right: 20px;
    font-size: 16px;
    color: #333;
}